bonjour
A = x² + 5 x + 4 x + 20 = x² + 9 x + 20
B = x² + 8 x - 3 x - 24 = x² + 5 x - 24
C = 2 y² + 6 y + y + 3 = 2 y² + 7 y + 3
D = y - 4 - y² /4 + 4 y / 4 = - y² /4 + 2 y- 4
E = 2 a² /2 - 1 /2 + 2 a - 1 = a² + 2 a - 1.5
F = 3 a + 3 - 2 a² - 2 a = - 2 a² + a + 3